The present invention relates to direct contact steam injection heaters. More specifically, the present invention relates to an improvement for controlling the amount of steam flow into the liquid being heated while also providing a liquid tight seal during a completely closed condition.
In direct contact steam injection heaters, steam and/or any other gaseous elements are directly mixed with a liquid being heated, or in some cases with a slurry being heated. Direct contact steam injection heaters are very effective at transferring heat energy from steam to the liquid. The injection heater provides rapid heat transfer with virtually no heat loss to atmosphere, and also transfers both the latent and the available sensible heat of the steam to the liquid.
The present invention was developed during ongoing development efforts by the assignee in the field of direct contact steam injection heaters. U.S. Pat. Nos. 5,622,655; 5,842,497; 6,082,712; 6,361,025 and 7,152,851 all represent some of the prior art developments in direct contact steam injection heaters by the assignee, and are hereby incorporated by reference.